C-glycosides have been demonstrated to have distinct biological functions and therefore display notable pharmacological values,whereas the access to the versatile structural analog of C-glycosides is a significant cha...C-glycosides have been demonstrated to have distinct biological functions and therefore display notable pharmacological values,whereas the access to the versatile structural analog of C-glycosides is a significant challenge to their advancement as therapeutic agents.We herein disclose a facial and efficient catalytic C-glycosylation using a glycosyl ortho-2,2-dimethoxycarbony lcyclopropylbenzoate(CCBz)as the donor.The trailblazing glycosyl donor can be simply activated by a non-toxic and easily accessible Sc(Ⅲ)catalyst.The ring-strain release of the incorporated donor-acceptor cyclopropane(DAC)serves as a powerful driving force of the glycosylation system.The adaptability of current methods to different types of donors and acceptors was exemplified.Examinations on the synthetic potential were done with the one-pot synthesis of free C-indolyl-glycosides and the subsequent biological studies,unlocking the antibacterial potentials of these compounds.展开更多
This document describes the creation of an informative Web GIS aimed at mitigating the impacts of flooding in the municipality of Ouagadougou, in Burkina Faso, a region that is highly sensitive to climate change. Burk...This document describes the creation of an informative Web GIS aimed at mitigating the impacts of flooding in the municipality of Ouagadougou, in Burkina Faso, a region that is highly sensitive to climate change. Burkina Faso, which is undergoing rapid urbanization, faces major natural threats, particularly flooding, as demonstrated by the severe floods of 2009 that caused loss of life, injury, structural damage and economic losses in Ouagadougou. The aim of this research is to develop a web map highlighting the municipality’s flood-prone areas, with a view to informing and raising awareness of flood risk reduction. Using the Leaflet JavaScript mapping library, the study uses HTML, CSS and JavaScript to implement web mapping technology. Data on Ouagadougou’s flood zones is generated by a multi-criteria analysis combining Saaty’s AHP method and GIS in QGIS, integrating seven (7) parameters including hydrography, altitude, slope, rainfall, soil types, land use and soil moisture index. QGIS processes and maps the themes, PostgreSQL with PostGIS serves as the DBMS and GeoServer functions as the map server. The Web GIS platform allows users to visualize the different flood risks, from very low to very high, or the high-risk areas specific to Ouagadougou. The AHP calculations classify the municipality into five flood vulnerability zones: very low (24.48%), low (27.93%), medium (23.01%), high (17.11%) and very high (7.47%). Effective risk management requires communication and awareness-raising. This online mapping application serves as a tool for communication, management and flood prevention in Ouagadougou, helping to mitigate flood-related natural disasters.展开更多
AIM:To elucidate the effects of melatonin on cisplatininduced hepatocellular carcinoma(HepG2) cell death and to identify potential cross-talk pathways.METHODS:Hepatocellular carcinoma HepG2 cells were treated with mel...AIM:To elucidate the effects of melatonin on cisplatininduced hepatocellular carcinoma(HepG2) cell death and to identify potential cross-talk pathways.METHODS:Hepatocellular carcinoma HepG2 cells were treated with melatonin and/or cisplatin for 24 to 48 h.Cell viability and the 50% cytotoxic concentration(CC50) were calculated by MTT assays.The effects and intracellular events induced by the selected concentrations of melatonin(1 mmol/L) and cisplatin(20 μmol/L) were investigated.Cell death and survival detection were primarily evaluated using a fluorescence microscope to assess 4',6 diamideno-2-phenylindol DNA staining and acridine orange lysosome staining and then further analyzed with immunocytochemistry using an anti-LC3 antibody.The potential molecularresponses mediated by melatonin against cisplatin after the combined treatment were investigated by reverse transcription-polymerase chains reaction and Western blot analyses of the genes and proteins associated with cell survival and death.A cell cycle analysis was performed using a flow cytometry assay.RESULTS:Melatonin had a concentration-dependent effect on HepG2 cell viability.At 1 mmol/L,melatonin significantly increased the cell viability percentage and decreased reactive oxygen species production due to cisplatin.Melatonin reduced cisplatin-induced cell death,decreasing phosphorylated p53 apoptotic protein,cleaved caspase 3 and Bax levels but increasing anti-apoptotic Bcl-2 gene and protein expression.When combined with cisplatin,melatonin induced S phase(DNA synthesis) cell cycle arrest and promoted autophagic events in HepG2 cells.Melatonin also had a concentration-dependent effect on Beclin-1 and its autophagic regulator mammalian target of rapamycin(mTOR) as well as the DNA excision repair cross complementary 1(ERCC1) protein.The expression levels of these proteins were altered in HepG2 cells during cisplatin or melatonin treatment alone.In the combination treatment,melatonin reversed the effects of cisplatin by suppressing the over-expression of mTOR and ERCC 1 and enhancing the expression levels of Beclin-1 and microtubule-associated protein-light chain3-Ⅱ,leading to intracellular autophagosome progression.CONCLUSION:Melatonin attenuated cisplatin-induced cell death in HepG2 cells via a counter-balance between the roles of apoptotic- and autophagy-related proteins.展开更多
Non-graphitized carbon(NGC)has been extensively utilized as carbonaceous anode in sodium-ion batteries(SIBs).However,more optimization to achieve competitive capacity and stability is still challenging for SIBs.In the...Non-graphitized carbon(NGC)has been extensively utilized as carbonaceous anode in sodium-ion batteries(SIBs).However,more optimization to achieve competitive capacity and stability is still challenging for SIBs.In the study,the dopant strategy is utilized to construct nitrogen/sulfur-doped non-graphitized carbon(N-NGC or S-NGC)shell decorated on three-dimensional graphene foam(GF)as a self-support electrode.The highly disordered microstructures of heteroatom doped carbons are produced by applying a low-temperature pyrolysis treatment to precursors containing nitrogen and sulfur.The DFT calculations of Na-ion adsorption energies at diverse heteroatom sites show marginal-S,pyrrolic N and pyridinic N with more intensive Na-ion adsorption ability than middle-S,C=O and pristine carbon.The N-NGC with dominant small graphitic regions delivers adsorption ability to Na-ion,while the S-NGC with significant single carbon lattice stripes demonstrates redox reaction with Na-ion.Evidently,in comparison with only adsorption-driven slope regions at high potential for N-NGC,the redox reaction-generated potentialplateau enables non-graphitized S-NGC superior discharge/charge capacity and cycle-stability in the slope region.This work could provide deep insight into the rational design of non-graphitized carbon with rich microstructure and composition.展开更多
This study aims to analyze temporal changes in land use and land cover change (LUCC) as well as identify areas for natural regeneration and potential areas for forest restoration in the Huasteca region for the period ...This study aims to analyze temporal changes in land use and land cover change (LUCC) as well as identify areas for natural regeneration and potential areas for forest restoration in the Huasteca region for the period from 1976 to 2007. Changes were quantified in numbers and, additionally, cartography was used to identify and map the main affected areas. Different models based on Geographic Information Systems (GIS) demonstrated that LUCC have occurred on an area of 11718.82 km2, representing 17.84% of the region’s surface. Agriculture and the growth of pasture could be identified as the main human-induced activities that have led to landscape modification. In addition, forest cover is affected by a deforestation rate which is higher than the national average. Further important changes include a change from natural land cover to non-original land cover, affecting an area of 4911.88 km2 in the period from 1976-1993, and an area of 1892.5 km2 in the period from 1993-2002. Smaller changes could be observed for the period from 1993-2002 with an affected area of 1029.78 km2. At the same time, a natural regeneration from nonoriginal to original land cover took place from 1976-1993 on an area of 1318.68 km2, and also on an area of 974.18 km2 between 1993 an 2002. The surface that underwent a natural regeneration of forest cover made up 1932.07 km2. At the same time, an area of 5739.29 km2 for potential forest restoration was identified. Drawing on GIS methods and techniques, the development of thematic maps for land use, land use and land cover changes for the years of analysis (1976-1993-2002-2007) proved to be very adequate for the evaluation and analysis of the land cover and land use change, in particular with regard to the decrease of natural vegetation cover.展开更多
Many organizations have now adopted Service Oriented Architecture （SOA） as an architectural style to help them with architecture, design and implementation of their core services and systems. Most of these organizat...Many organizations have now adopted Service Oriented Architecture （SOA） as an architectural style to help them with architecture, design and implementation of their core services and systems. Most of these organizations are challenged in integrating SOA style with their overall Enterprise Architecture work. This framework links an SOA style with the Enterprise Architecture （EA） methodologies to help organizations organize their SOA effort as a key part of their Enterprise Architecture. The case study demonstrates the implementation of architecture goal with organization vision in service oriented organizational structure using services that align Business with Technology. The framework is validated and has reserved the privileges of SOA and EA.展开更多
Background: Modelling aboveground biomass(AGB) in forest and woodland ecosystems is critical for accurate estimation of carbon stocks. However, scarcity of allometric models for predicting AGB remains an issue that ha...Background: Modelling aboveground biomass(AGB) in forest and woodland ecosystems is critical for accurate estimation of carbon stocks. However, scarcity of allometric models for predicting AGB remains an issue that has not been adequately addressed in Africa. In particular, locally developed models for estimating AGB in the tropical woodlands of Ghana have received little attention. In the absence of locally developed allometric models, Ghana will continue to use Tier 1 biomass data through the application of pantropic models. Without local allometric models it is not certain how Ghana would achieve Tier 2 and 3 levels under the United Nations programme for reducing emissions from deforestation and forest degradation. The objective of this study is to develop a mixedspecies allometric model for use in estimating AGB for the tropical woodlands in Ghana. Destructive sampling was carried out on 745 trees(as part of charcoal production) for the development of allometric equations. Diameter at breast height(dbh, i.e. 1.3 m above ground level), total tree height(H) and wood density(ρ) were used as predictors for the models. Seven models were compared and the best model selected based on model efficiency,bias(%) and corrected Akaike Information Criterion. The best model was validated by comparing its results with those of the pantropic model developed by Chave et al.(Glob Chang Biol 20:3177–3190, 2014) using equivalence test and conventional paired t-test.Results: The results revealed that the best model for estimating AGB in the tropical woodlands is AGB =0.0580ρ((dbh)2 H)0.999. The equivalence test showed that this model and the pantropic model developed by Chave et al.(Glob Chang Biol 20:3177–3190, 2014) were equivalent within ±10% of their mean predictions(p-values <0.0001 for one-tailed t-tests for both lower and upper bounds at 5% significant level), while the paired t-test revealed that the mean(181.44 ± 18.25 kg) of the model predictions of the best model of this study was significantly(n = 745, mean diff. = 16.50 ± 2.45 kg;S.E. = 1.25 kg;p < 0.001) greater than that(164.94 ± 15.82 kg) of the pantropic model of Chave et al.(Glob Chang Biol 20:3177–3190, 2014).Conclusion: The model developed in this study fills a critical gap in estimating AGB in tropical woodlands in Ghana and other West African countries with similar ecological conditions. Despite the equivalence with the pantropic model it remains superior to the model of Chave et al.(Glob Chang Biol 20:3177–3190, 2014) for the estimation of AGB in local tropical woodlands. It is a relevant tool for the attainment of Tier 2 and 3 levels for REDD+. The model is recommended for use in the tropical woodlands in Ghana and other West African countries in place of the use of pantropic models.展开更多
This work aims the deterministic dynamic analysis,in the time and frequency domain,of a reinforced concrete floor supported by a pre-cast pile foundation system,when subjected to the excitation produced by a large com...This work aims the deterministic dynamic analysis,in the time and frequency domain,of a reinforced concrete floor supported by a pre-cast pile foundation system,when subjected to the excitation produced by a large compressor installed in an industry for the production of air gases.The concrete slab presents a dimension of 12 m×15 m,required to support a compressor-motor assembly weighting 1,900 kN and positioned at a height of 4m of the investigated concrete floor.In this investigation,two numerical models were developed and the difference between these models is characterized by the discretization of the support points(pre-cast concrete piles).The developed numerical model adopted the usual mesh refinement techniques present in finite element method simulations implemented in the CSi SAP2000 V.17.2.0 software.Based on the developed analysis methodology,the dynamic structural response of the foundation system is evaluated in terms of natural frequencies,vibration modes,displacements,velocities,and accelerations.The maximum values of the dynamic response of the system are compared with the limit values recommended by standards and project recommendations,aiming a careful evaluation,regarding the performance of the structure in terms of excessive vibrations and the economic aspects involved in the design of the foundation system.Finally,the obtained results of the two developed numerical models are compared,as to evaluate if there are benefits in refining the support points modelling.展开更多
The threat to human, fauna and flora life posed by pollution due to gas flaring cannot be over-emphasized. Gas flared often resulted in some environmental degradation, one of such influence is soil pollution and poor ...The threat to human, fauna and flora life posed by pollution due to gas flaring cannot be over-emphasized. Gas flared often resulted in some environmental degradation, one of such influence is soil pollution and poor crop yield. This study examined the effect of gas flaring on soil and cassava productivity in Ebedei, Ukwuani LGA, Delta State. For the purpose of data collection, five (5) experimental sites were systematically selected around the flare site in Ebedei and a control site at Obiaruku. Soil samples were collected at surface 0 - 10 cm and 10 - 20 cm at distance of 50 m, 100 m, 150 m, 200 m and 250 m apart respectively away from the bund wall of the flare. The data generated were analysed using multiple regression and paired t-test analyses. The study revealed that the soils found in Ebedei have high composition of sand and soil temperature and are acidic. The soil electrical conductivity, Phosphorous, Nitrogen, Potassium and Sodium were very low. More so, the yield of cassava increases with a corresponding increase in distances from flare site. The first hypothesis revealed that there is significant variation in soil nutrients as distance increases from gas flare sites. This is evident from F value of 234.99 which is greater than the critical table value of 4.39. Furthermore, as flare distance increases, so also the organic carbon, electrical conductivity and Nitrogen increase. The second hypothesis revealed that there is a significant difference in cassava yield at gas-flared area and the non-flared area which is evident at t (6.032) is greater than the critical table (1.895) at P 0.05. It is therefore recommended that Government and FEPA should enact environmental Policies and revisit and review existing environmental and oil drilling laws in Nigeria with a view of updating them to international and environmental friendly standards.展开更多
The aim of this work was to study the use of coal waste to produce concrete paving blocks. The methodology considered the following steps: sampling of a coal mining waste;gravity separation of the fraction with specif...The aim of this work was to study the use of coal waste to produce concrete paving blocks. The methodology considered the following steps: sampling of a coal mining waste;gravity separation of the fraction with specific gravity between 2.4 and 2.8;comminution of the material and particle size analysis;technological characterization of the material and the production of concrete paving blocks. The results showed that the coal waste considered in this work can be used to replace conventional sand as a fine aggregate for concrete paving blocks. This practice can collaborate in a cleaner coal production.展开更多
One of the impacts resulting from mining process is the occurrence of AMD(Acid Mine Drainage),which is rainwater or groundwater mixed with rock.AMD contains specific sulfides in coal,leading to highly acidic water wit...One of the impacts resulting from mining process is the occurrence of AMD(Acid Mine Drainage),which is rainwater or groundwater mixed with rock.AMD contains specific sulfides in coal,leading to highly acidic water with elevated concentrations of iron and manganese.Furthermore,phytoremediation offers a method to enhance specific contaminant levels in various environmental mediums,including soil,sediment,dirt or sludge,groundwater,and surface water.This waste treatment approach employs readily applicable,efficient,and effective plant species,such as burhead or Amazon sword,Melati air(Echinodorus palaefolius),Water hyacinth or eceng gondok(Eichhornia crassipes),and globe fimbry or Mendong(Fimbritylis globulosa)which are aquatic plants in South Sumatra with the capacity to absorb heavy metals.Therefore,this study aims to measure the growth response of each aquatic plant(Echinodorus palaefolius,Eichhornia crassipes,and Fimbritylis globulosa)in each treatment.It also analyzes the amount of heavy metal uptake in the form of Fe and Mn by each aquatic plant(Eichhornia crassipes,Echinodorus palaefolius,and Fimbritylis globulosa)used.Additionally,it investigates the ability of these plants to facilitate the phytoremediation of AMD using compost derived from OPEFB(Oil Palm Empty Fruit Bunches)to reduce the presence of Fe and Mn elements.The study employs a bioreactor and encompasses two treatment factors,namely the type of aquatic plants(Echinodorus palaefolius,Eichhornia crassipes,and Fimbritylis globulosa)and the composition comparison between OPEFB compost and limestone.The result shows that the combination of treatments in terms of plant types and media composition yields the highest growth,with a weight of 286.25 g in T2K1 treatment.This involves Eceng gondok and a media composition of compost to limestone in a ratio of 50%to 50%.Moreover,Mendong exhibits the highest absorption of Fe metal,with a value of 0.82 g,followed by Eceng gondok with 0.55 g,while Melati displays the lowest at 0.38 g.Regarding the absorption of Mn,Eceng gondok demonstrates the highest uptake,measuring 0.36 g,followed by Melati and Mendong at 0.11 g and 0.06 g,respectively.展开更多
The expression“patient revolution”is the social,educational,cultural,and political movement initiated at the end of the twentieth century and beginning of the twenty-first century,which sustains the protagonism of t...The expression“patient revolution”is the social,educational,cultural,and political movement initiated at the end of the twentieth century and beginning of the twenty-first century,which sustains the protagonism of the patients in their care as the primary decision maker and holder of human rights.The patient revolution comprises varied approaches and references,such as Patient-Centered Care,Shared Decision-Making,Patient Participation,and Patients’Rights,which combine to uphold that the patient is a moral agent and anchor healthcare in the biopsychosocial model.In this sense,this movement is a new proposal of ethics for clinical practice.This theoretical research primary goal is to develop theoretical contributions that support this new Bioethics dimension,emphasizing the context in healthcare that calls for new ethics in clinical practice,characterized as a patient revolution movement.We concluded that the patient revolution had driven a new paradigm in healthcare based on Patient-Centricity,SDM,and Patients’Rights.Despite this critical change in the health sphere,the patient revolution appears to have reverberated in clinical bioethics.Thus,theoretical contributions must be developed for new ethics in the clinic,a task undertaken in this article through the proposal of Healthcare Bioethics as an adequate frame of reference to be adopted at all levels of clinical care.Thus,it is concluded that having Bioethics Healthcare as a beacon of ethics in clinical encounters can contribute to the quality of care and its ethical provision,confronting practices that violate Patients’Rights.It is imperative to change paternalistic theoretical frameworks that mitigate the Patients’Right to participate in every decision regarding their health.Only with the adoption of new approaches and an insight into the patient’s role in clinical interaction can a new culture in Patient-Centered healthcare take shape.展开更多
Transcription activator-like effectors(TALEs) mimic eukaryotic transcriptional activators and translocate into host plant cells via the bacterial type Ⅲ secretion system(T3SS) during pathogenic interactions. They pla...Transcription activator-like effectors(TALEs) mimic eukaryotic transcriptional activators and translocate into host plant cells via the bacterial type Ⅲ secretion system(T3SS) during pathogenic interactions. They play a crucial role in disease development by regulating host genes. Despite this, the regulatory mechanisms by which TALEs control OsWRKY transcription factors(TFs) remain poorly understood. In this study, we show that two TALEs from Xanthomonas oryzae pv. oryzae(Xoo) individually modulate two OsWRKY TFs, resulting in increased susceptibility and reduced host defense.Specifically, Xoo1219 and Xoo2145 activate the expression of OsWRKY104 and OsWRKY55, respectively, through direct interactions. OsWRKY104 increases the susceptibility to Xoo by activating OsSWEET11 and OsSWEET14, while OsWRKY55suppresses host defense against Xoo by directly regulating OsWRKY62. These findings suggest that TALEs hijack the host's OsWRKY TFs to create a favorable environment for bacterial survival.展开更多
Transitional metal oxides have a wide range of applications due to their superior properties.The enhanced performance of metal oxide relies on their desirable oxidation states,which is challenging to achieve and requi...Transitional metal oxides have a wide range of applications due to their superior properties.The enhanced performance of metal oxide relies on their desirable oxidation states,which is challenging to achieve and requires complex post-processes.This study demonstrates a facile strategy enabling rapid phase transformation of transition metal oxide.The approach involves synthesis of a tetragonal Mn_(3)O_(4)/carbon cloth composite using the liquid plasma discharge deposition(LPDD)technique,followed by laser irradiation with the presence of ethylene glycol under an N_(2)gas environment.The resulting face-centered cubic Mn O/carbon cloth electrode exhibits an excellent capacitance of 1,125 Fg_(-1)at 2 A g^(-1),with remarkable capacitance retention of 95%after 10,000 cycles.This approach can be extended to other transition metals including Co,Cu,Cr,Fe,Ni,and Zn.Computational simulations reveal the significance of ethylene glycol and the underlying mechanism associated with the phase transformation of transition metal oxides.The present study offers a powerful technique for the phase transformation of transition metal oxide which can guide the development of new electrode materials with enhanced electrochemical properties for high-performance energy storage applications.展开更多
This study investigates the spatiotemporal trends of key environmental drivers of dust emission over North Africa especially precipitation,surface wind speed,low vegetation leaf area index(LAI),and the Saharan Heat Lo...This study investigates the spatiotemporal trends of key environmental drivers of dust emission over North Africa especially precipitation,surface wind speed,low vegetation leaf area index(LAI),and the Saharan Heat Low(SHL).Using reanalysis data spanning the past four decades(1984-2023),we analyze the spatial trends and assess their statistical significance.The aim is to evaluate how long-term changes in these local meteorological drivers may have contributed to the observed decline in dust activity over North Africa.Results reveal a widespread increase in precipitation and LAI,particularly across the Sahel region(10˚N-20˚N),suggesting enhanced surface wetness and vegetation cover that act to suppress dust mobilization.Simultaneously,a significant negative trend in 10 m wind speed was observed across both the Sahel and parts of Sahara,limiting the surface wind stress required for dust uplift.In contrast,the SHL exhibited a notable intensification and westward expansion,especially over the southern Sahara.Although SHL strengthening is typically associated with increased dust activity,our findings point to a more nuanced role,wherein its recent expansion coincides with broader dust-suppressing environmental trends.These co-evolving changes provide a compelling mechanistic explanation for the observed decline in North African dust activity over recent decades and enhance our understanding and climate models capabilities related to dust activity over North Africa.展开更多
Carbonaceous materials with large interlayer spacing and disordered structure are considered suitable as electrodes in sodium-ion batteries so as to overcome the problem encountered in conventional electrodes.In this ...Carbonaceous materials with large interlayer spacing and disordered structure are considered suitable as electrodes in sodium-ion batteries so as to overcome the problem encountered in conventional electrodes.In this study,carbon quantum dots(CQDs)decorated with SnO_(2)and NaVO_(3)are used as electrodes in the fabrication of flexible Na-ion batteries.CQDs are prepared from dead leaves of the Samanea saman tree through alkaline-peroxide treatment and hydrothermal carbonization.As-prepared CQDs exhibit a quantum yield of 21.03%at an excitation wavelength of 360 nm.Various separators such as indium-doped tin oxide/polyoxyethylene tridecyl ether(ITO/PTE),rice paper(RP),silicone with three big holes(SIL BH),silicone with many small holes(SIL SH)and cellulose paper(CP)have been tried in flexible Na-ion batteries.SIL SH achieved higher specific capacitance(881 F g-1)than other separators due to the function of many small holes on the surface of the silicone.The SIL SH separator delivered higher discharge capacities of 141 and 114 mC g-1 at 1.5 and 2.5 V than SIL BH.The RP separator delivered specific discharge capacities of 1087 and 347 mC g-1 in the 1st and 50th cycles,respectively,at 1 V.The RP separator delivered a high initial specific discharge capacity of 698 mC g-1 at 2 V and maintained a good discharge capacity of 222 mC g-1 in the 50th cycle.As compared to RP,SIL SH delivered high specific discharge capacity of 4246 in 1st cycle at 2 V but maintained a capacity of 71 mC g-1 in the 50th cycle.This study reveals the scope of developing flexible Na-ion batteries with high capacity and cyclability using carbonaceous materials derived from the leaves of the S.saman tree.展开更多
Gel-polymer electrolytes with high thermal stability and mechanical properties were considered suitable in rechargeable batteries so as to overcome the problems encountered in liquid electrolytes.In a previous study,f...Gel-polymer electrolytes with high thermal stability and mechanical properties were considered suitable in rechargeable batteries so as to overcome the problems encountered in liquid electrolytes.In a previous study,flexible sodium-ion batteries(FSIBs)were fabri-cated using electrodes made of carbon quantum dots(CQDs)decorated with SnO_(2) and NaVO_(3) utilizing a polyvinyl alcohol(PVA)/P3HT gel-polymer electrolyte at a ratio of 1:0.05.In addition,various separators such as indium-doped tin oxide/polyoxyethylene tridecyl ether(ITO/PTE),rice paper(RP),silicone with three big holes(SIL BH),silicone with many small holes(SIL SH)and cellulose paper(CP)were tested in flexible Na-ion batteries.The SIL SH delivered a high specific discharge capacity of 4246 mAh g^(-1) in the initial cycle at 2 V and maintained a value of 71 mAh g^(-1) in the 50th cycle.With the aim of improving the cyclic ability of FSIBs,different weight ratios of PVA/P3HT(1:0.025,1:0.05,1:0.1,1:0.15,1:0.2)were tried in this work using the electrodes CQDs@SnO_(2) and CQDs@NaVO_(3).The above ratios were referred to as B25,B50,B100,B150 and B200,respectively.SIL SH was used as a separator.Cyclic voltammetry studies indicated that B150 had a high specific capacitance of 13062 F g^(-1).B25 and B100 exhibited high discharge capacities(171 mAh g^(-1))and(151 mAh g^(-1))compared to that of other ratios B50(75 mAh g^(-1)),B150(88 mAh g^(-1))and B200(54 mAh g^(-1))in the 50th cycle at 2.0 V.This study reveals the scope of developing FSIBs of high capacity and cyclability at different voltages using carbonaceous electrodes and gel-polymer electrolytes with different ratios of PVA/P3HT.The focus of the present study is to bring out the optimum ratio of PVA/P3HT for maximizing the cyclic ability of FSIBs.展开更多
Urban infrastructures are invariably constituted by social and technical components whose capacity to withstand crisis is determined by the resilience of their sociotechnical structures.This study aims to apply the pr...Urban infrastructures are invariably constituted by social and technical components whose capacity to withstand crisis is determined by the resilience of their sociotechnical structures.This study aims to apply the principles of sociotechnical resilience in modeling and simulating disaster response in urban areas.Drawing on a case study of Jakarta,Indonesia,our study focuses on the role of hospitals as part of healthcare infrastructure in response to a large-scale disaster.Each hospital is modeled as a coordinated location with a certain amount of resources,primarily in terms of medical staff.We perform sensitivity analysis through Monte Carlo simulations to observe the impacts of various response strategies,disaster severity,and communication duration on system resilience.The results show that centralized systems are generally more suitable for dealing with low disaster severity,while the decentralized strategy performs better during a disaster with worse impacts.Additionally,the time taken for communication and coordination can significantly affect the performance of centralized systems.By simulating various scenarios,parameters,and recovery protocols,the model we developed can help policymakers,city planners,and other stakeholders design proper response strategies suitable to their structural conditions and available resources during a large-scale disaster in urban cities.展开更多
Silica nanoparticles have been studied extensively in biomedical field due to their high biocompatibility,controllable morphology and so on.They can be used both as the drug carrier and imaging vehicle.Here,an aminate...Silica nanoparticles have been studied extensively in biomedical field due to their high biocompatibility,controllable morphology and so on.They can be used both as the drug carrier and imaging vehicle.Here,an aminated ultra-small silica nanoparticle based system is developed with various functionalities.Multiple molecules including fluorophore,folic acid,and antibody are coupled to this system to achieve specific applications such as bacterial/cell labelling and recognition.展开更多
基金Ministry of Education(MOE-T2EP30120-0007,Tier-1 RG107/23)of Singapore for the financial support.
文摘C-glycosides have been demonstrated to have distinct biological functions and therefore display notable pharmacological values,whereas the access to the versatile structural analog of C-glycosides is a significant challenge to their advancement as therapeutic agents.We herein disclose a facial and efficient catalytic C-glycosylation using a glycosyl ortho-2,2-dimethoxycarbony lcyclopropylbenzoate(CCBz)as the donor.The trailblazing glycosyl donor can be simply activated by a non-toxic and easily accessible Sc(Ⅲ)catalyst.The ring-strain release of the incorporated donor-acceptor cyclopropane(DAC)serves as a powerful driving force of the glycosylation system.The adaptability of current methods to different types of donors and acceptors was exemplified.Examinations on the synthetic potential were done with the one-pot synthesis of free C-indolyl-glycosides and the subsequent biological studies,unlocking the antibacterial potentials of these compounds.
文摘This document describes the creation of an informative Web GIS aimed at mitigating the impacts of flooding in the municipality of Ouagadougou, in Burkina Faso, a region that is highly sensitive to climate change. Burkina Faso, which is undergoing rapid urbanization, faces major natural threats, particularly flooding, as demonstrated by the severe floods of 2009 that caused loss of life, injury, structural damage and economic losses in Ouagadougou. The aim of this research is to develop a web map highlighting the municipality’s flood-prone areas, with a view to informing and raising awareness of flood risk reduction. Using the Leaflet JavaScript mapping library, the study uses HTML, CSS and JavaScript to implement web mapping technology. Data on Ouagadougou’s flood zones is generated by a multi-criteria analysis combining Saaty’s AHP method and GIS in QGIS, integrating seven (7) parameters including hydrography, altitude, slope, rainfall, soil types, land use and soil moisture index. QGIS processes and maps the themes, PostgreSQL with PostGIS serves as the DBMS and GeoServer functions as the map server. The Web GIS platform allows users to visualize the different flood risks, from very low to very high, or the high-risk areas specific to Ouagadougou. The AHP calculations classify the municipality into five flood vulnerability zones: very low (24.48%), low (27.93%), medium (23.01%), high (17.11%) and very high (7.47%). Effective risk management requires communication and awareness-raising. This online mapping application serves as a tool for communication, management and flood prevention in Ouagadougou, helping to mitigate flood-related natural disasters.
基金Supported by Center of Excellence on Environmental Health and Toxicology,Science and Technology Postgraduate Education and Research Development Office,Thailand Ministry of Education
文摘AIM:To elucidate the effects of melatonin on cisplatininduced hepatocellular carcinoma(HepG2) cell death and to identify potential cross-talk pathways.METHODS:Hepatocellular carcinoma HepG2 cells were treated with melatonin and/or cisplatin for 24 to 48 h.Cell viability and the 50% cytotoxic concentration(CC50) were calculated by MTT assays.The effects and intracellular events induced by the selected concentrations of melatonin(1 mmol/L) and cisplatin(20 μmol/L) were investigated.Cell death and survival detection were primarily evaluated using a fluorescence microscope to assess 4',6 diamideno-2-phenylindol DNA staining and acridine orange lysosome staining and then further analyzed with immunocytochemistry using an anti-LC3 antibody.The potential molecularresponses mediated by melatonin against cisplatin after the combined treatment were investigated by reverse transcription-polymerase chains reaction and Western blot analyses of the genes and proteins associated with cell survival and death.A cell cycle analysis was performed using a flow cytometry assay.RESULTS:Melatonin had a concentration-dependent effect on HepG2 cell viability.At 1 mmol/L,melatonin significantly increased the cell viability percentage and decreased reactive oxygen species production due to cisplatin.Melatonin reduced cisplatin-induced cell death,decreasing phosphorylated p53 apoptotic protein,cleaved caspase 3 and Bax levels but increasing anti-apoptotic Bcl-2 gene and protein expression.When combined with cisplatin,melatonin induced S phase(DNA synthesis) cell cycle arrest and promoted autophagic events in HepG2 cells.Melatonin also had a concentration-dependent effect on Beclin-1 and its autophagic regulator mammalian target of rapamycin(mTOR) as well as the DNA excision repair cross complementary 1(ERCC1) protein.The expression levels of these proteins were altered in HepG2 cells during cisplatin or melatonin treatment alone.In the combination treatment,melatonin reversed the effects of cisplatin by suppressing the over-expression of mTOR and ERCC 1 and enhancing the expression levels of Beclin-1 and microtubule-associated protein-light chain3-Ⅱ,leading to intracellular autophagosome progression.CONCLUSION:Melatonin attenuated cisplatin-induced cell death in HepG2 cells via a counter-balance between the roles of apoptotic- and autophagy-related proteins.
基金supported by the National Natural Science Foundation of China(52272296,51502092)the Fundamental Research Funds for the Central Universities(JKD01211601,1222201718002)+1 种基金the National Overseas High-Level Talent Youth Program in Chinathe Eastern Scholar Project of Shanghai。
文摘Non-graphitized carbon(NGC)has been extensively utilized as carbonaceous anode in sodium-ion batteries(SIBs).However,more optimization to achieve competitive capacity and stability is still challenging for SIBs.In the study,the dopant strategy is utilized to construct nitrogen/sulfur-doped non-graphitized carbon(N-NGC or S-NGC)shell decorated on three-dimensional graphene foam(GF)as a self-support electrode.The highly disordered microstructures of heteroatom doped carbons are produced by applying a low-temperature pyrolysis treatment to precursors containing nitrogen and sulfur.The DFT calculations of Na-ion adsorption energies at diverse heteroatom sites show marginal-S,pyrrolic N and pyridinic N with more intensive Na-ion adsorption ability than middle-S,C=O and pristine carbon.The N-NGC with dominant small graphitic regions delivers adsorption ability to Na-ion,while the S-NGC with significant single carbon lattice stripes demonstrates redox reaction with Na-ion.Evidently,in comparison with only adsorption-driven slope regions at high potential for N-NGC,the redox reaction-generated potentialplateau enables non-graphitized S-NGC superior discharge/charge capacity and cycle-stability in the slope region.This work could provide deep insight into the rational design of non-graphitized carbon with rich microstructure and composition.
文摘This study aims to analyze temporal changes in land use and land cover change (LUCC) as well as identify areas for natural regeneration and potential areas for forest restoration in the Huasteca region for the period from 1976 to 2007. Changes were quantified in numbers and, additionally, cartography was used to identify and map the main affected areas. Different models based on Geographic Information Systems (GIS) demonstrated that LUCC have occurred on an area of 11718.82 km2, representing 17.84% of the region’s surface. Agriculture and the growth of pasture could be identified as the main human-induced activities that have led to landscape modification. In addition, forest cover is affected by a deforestation rate which is higher than the national average. Further important changes include a change from natural land cover to non-original land cover, affecting an area of 4911.88 km2 in the period from 1976-1993, and an area of 1892.5 km2 in the period from 1993-2002. Smaller changes could be observed for the period from 1993-2002 with an affected area of 1029.78 km2. At the same time, a natural regeneration from nonoriginal to original land cover took place from 1976-1993 on an area of 1318.68 km2, and also on an area of 974.18 km2 between 1993 an 2002. The surface that underwent a natural regeneration of forest cover made up 1932.07 km2. At the same time, an area of 5739.29 km2 for potential forest restoration was identified. Drawing on GIS methods and techniques, the development of thematic maps for land use, land use and land cover changes for the years of analysis (1976-1993-2002-2007) proved to be very adequate for the evaluation and analysis of the land cover and land use change, in particular with regard to the decrease of natural vegetation cover.
文摘Many organizations have now adopted Service Oriented Architecture （SOA） as an architectural style to help them with architecture, design and implementation of their core services and systems. Most of these organizations are challenged in integrating SOA style with their overall Enterprise Architecture work. This framework links an SOA style with the Enterprise Architecture （EA） methodologies to help organizations organize their SOA effort as a key part of their Enterprise Architecture. The case study demonstrates the implementation of architecture goal with organization vision in service oriented organizational structure using services that align Business with Technology. The framework is validated and has reserved the privileges of SOA and EA.
基金Federal Ministry of Education and Research (BMBF) of Germany,funded the PhD programme of the lead author through the West African Science Service Centre for Climate Change and Adapted Land use (WASCAL)。
文摘Background: Modelling aboveground biomass(AGB) in forest and woodland ecosystems is critical for accurate estimation of carbon stocks. However, scarcity of allometric models for predicting AGB remains an issue that has not been adequately addressed in Africa. In particular, locally developed models for estimating AGB in the tropical woodlands of Ghana have received little attention. In the absence of locally developed allometric models, Ghana will continue to use Tier 1 biomass data through the application of pantropic models. Without local allometric models it is not certain how Ghana would achieve Tier 2 and 3 levels under the United Nations programme for reducing emissions from deforestation and forest degradation. The objective of this study is to develop a mixedspecies allometric model for use in estimating AGB for the tropical woodlands in Ghana. Destructive sampling was carried out on 745 trees(as part of charcoal production) for the development of allometric equations. Diameter at breast height(dbh, i.e. 1.3 m above ground level), total tree height(H) and wood density(ρ) were used as predictors for the models. Seven models were compared and the best model selected based on model efficiency,bias(%) and corrected Akaike Information Criterion. The best model was validated by comparing its results with those of the pantropic model developed by Chave et al.(Glob Chang Biol 20:3177–3190, 2014) using equivalence test and conventional paired t-test.Results: The results revealed that the best model for estimating AGB in the tropical woodlands is AGB =0.0580ρ((dbh)2 H)0.999. The equivalence test showed that this model and the pantropic model developed by Chave et al.(Glob Chang Biol 20:3177–3190, 2014) were equivalent within ±10% of their mean predictions(p-values <0.0001 for one-tailed t-tests for both lower and upper bounds at 5% significant level), while the paired t-test revealed that the mean(181.44 ± 18.25 kg) of the model predictions of the best model of this study was significantly(n = 745, mean diff. = 16.50 ± 2.45 kg;S.E. = 1.25 kg;p < 0.001) greater than that(164.94 ± 15.82 kg) of the pantropic model of Chave et al.(Glob Chang Biol 20:3177–3190, 2014).Conclusion: The model developed in this study fills a critical gap in estimating AGB in tropical woodlands in Ghana and other West African countries with similar ecological conditions. Despite the equivalence with the pantropic model it remains superior to the model of Chave et al.(Glob Chang Biol 20:3177–3190, 2014) for the estimation of AGB in local tropical woodlands. It is a relevant tool for the attainment of Tier 2 and 3 levels for REDD+. The model is recommended for use in the tropical woodlands in Ghana and other West African countries in place of the use of pantropic models.
文摘This work aims the deterministic dynamic analysis,in the time and frequency domain,of a reinforced concrete floor supported by a pre-cast pile foundation system,when subjected to the excitation produced by a large compressor installed in an industry for the production of air gases.The concrete slab presents a dimension of 12 m×15 m,required to support a compressor-motor assembly weighting 1,900 kN and positioned at a height of 4m of the investigated concrete floor.In this investigation,two numerical models were developed and the difference between these models is characterized by the discretization of the support points(pre-cast concrete piles).The developed numerical model adopted the usual mesh refinement techniques present in finite element method simulations implemented in the CSi SAP2000 V.17.2.0 software.Based on the developed analysis methodology,the dynamic structural response of the foundation system is evaluated in terms of natural frequencies,vibration modes,displacements,velocities,and accelerations.The maximum values of the dynamic response of the system are compared with the limit values recommended by standards and project recommendations,aiming a careful evaluation,regarding the performance of the structure in terms of excessive vibrations and the economic aspects involved in the design of the foundation system.Finally,the obtained results of the two developed numerical models are compared,as to evaluate if there are benefits in refining the support points modelling.
文摘The threat to human, fauna and flora life posed by pollution due to gas flaring cannot be over-emphasized. Gas flared often resulted in some environmental degradation, one of such influence is soil pollution and poor crop yield. This study examined the effect of gas flaring on soil and cassava productivity in Ebedei, Ukwuani LGA, Delta State. For the purpose of data collection, five (5) experimental sites were systematically selected around the flare site in Ebedei and a control site at Obiaruku. Soil samples were collected at surface 0 - 10 cm and 10 - 20 cm at distance of 50 m, 100 m, 150 m, 200 m and 250 m apart respectively away from the bund wall of the flare. The data generated were analysed using multiple regression and paired t-test analyses. The study revealed that the soils found in Ebedei have high composition of sand and soil temperature and are acidic. The soil electrical conductivity, Phosphorous, Nitrogen, Potassium and Sodium were very low. More so, the yield of cassava increases with a corresponding increase in distances from flare site. The first hypothesis revealed that there is significant variation in soil nutrients as distance increases from gas flare sites. This is evident from F value of 234.99 which is greater than the critical table value of 4.39. Furthermore, as flare distance increases, so also the organic carbon, electrical conductivity and Nitrogen increase. The second hypothesis revealed that there is a significant difference in cassava yield at gas-flared area and the non-flared area which is evident at t (6.032) is greater than the critical table (1.895) at P 0.05. It is therefore recommended that Government and FEPA should enact environmental Policies and revisit and review existing environmental and oil drilling laws in Nigeria with a view of updating them to international and environmental friendly standards.
文摘The aim of this work was to study the use of coal waste to produce concrete paving blocks. The methodology considered the following steps: sampling of a coal mining waste;gravity separation of the fraction with specific gravity between 2.4 and 2.8;comminution of the material and particle size analysis;technological characterization of the material and the production of concrete paving blocks. The results showed that the coal waste considered in this work can be used to replace conventional sand as a fine aggregate for concrete paving blocks. This practice can collaborate in a cleaner coal production.
文摘One of the impacts resulting from mining process is the occurrence of AMD(Acid Mine Drainage),which is rainwater or groundwater mixed with rock.AMD contains specific sulfides in coal,leading to highly acidic water with elevated concentrations of iron and manganese.Furthermore,phytoremediation offers a method to enhance specific contaminant levels in various environmental mediums,including soil,sediment,dirt or sludge,groundwater,and surface water.This waste treatment approach employs readily applicable,efficient,and effective plant species,such as burhead or Amazon sword,Melati air(Echinodorus palaefolius),Water hyacinth or eceng gondok(Eichhornia crassipes),and globe fimbry or Mendong(Fimbritylis globulosa)which are aquatic plants in South Sumatra with the capacity to absorb heavy metals.Therefore,this study aims to measure the growth response of each aquatic plant(Echinodorus palaefolius,Eichhornia crassipes,and Fimbritylis globulosa)in each treatment.It also analyzes the amount of heavy metal uptake in the form of Fe and Mn by each aquatic plant(Eichhornia crassipes,Echinodorus palaefolius,and Fimbritylis globulosa)used.Additionally,it investigates the ability of these plants to facilitate the phytoremediation of AMD using compost derived from OPEFB(Oil Palm Empty Fruit Bunches)to reduce the presence of Fe and Mn elements.The study employs a bioreactor and encompasses two treatment factors,namely the type of aquatic plants(Echinodorus palaefolius,Eichhornia crassipes,and Fimbritylis globulosa)and the composition comparison between OPEFB compost and limestone.The result shows that the combination of treatments in terms of plant types and media composition yields the highest growth,with a weight of 286.25 g in T2K1 treatment.This involves Eceng gondok and a media composition of compost to limestone in a ratio of 50%to 50%.Moreover,Mendong exhibits the highest absorption of Fe metal,with a value of 0.82 g,followed by Eceng gondok with 0.55 g,while Melati displays the lowest at 0.38 g.Regarding the absorption of Mn,Eceng gondok demonstrates the highest uptake,measuring 0.36 g,followed by Melati and Mendong at 0.11 g and 0.06 g,respectively.
文摘The expression“patient revolution”is the social,educational,cultural,and political movement initiated at the end of the twentieth century and beginning of the twenty-first century,which sustains the protagonism of the patients in their care as the primary decision maker and holder of human rights.The patient revolution comprises varied approaches and references,such as Patient-Centered Care,Shared Decision-Making,Patient Participation,and Patients’Rights,which combine to uphold that the patient is a moral agent and anchor healthcare in the biopsychosocial model.In this sense,this movement is a new proposal of ethics for clinical practice.This theoretical research primary goal is to develop theoretical contributions that support this new Bioethics dimension,emphasizing the context in healthcare that calls for new ethics in clinical practice,characterized as a patient revolution movement.We concluded that the patient revolution had driven a new paradigm in healthcare based on Patient-Centricity,SDM,and Patients’Rights.Despite this critical change in the health sphere,the patient revolution appears to have reverberated in clinical bioethics.Thus,theoretical contributions must be developed for new ethics in the clinic,a task undertaken in this article through the proposal of Healthcare Bioethics as an adequate frame of reference to be adopted at all levels of clinical care.Thus,it is concluded that having Bioethics Healthcare as a beacon of ethics in clinical encounters can contribute to the quality of care and its ethical provision,confronting practices that violate Patients’Rights.It is imperative to change paternalistic theoretical frameworks that mitigate the Patients’Right to participate in every decision regarding their health.Only with the adoption of new approaches and an insight into the patient’s role in clinical interaction can a new culture in Patient-Centered healthcare take shape.
基金support of the Next-Generation BioGreen 21 Program of the Rural Development Administration(PJ013269)the Brain Pool Program of the Ministry of Science and ICT through the National Research Foundation of Korea(RS-2023-00262576)M.-Y.J.was supported by an NRF grant funded by the Korean government(Ministry of Science and ICT)(RS-2025000518246).
文摘Transcription activator-like effectors(TALEs) mimic eukaryotic transcriptional activators and translocate into host plant cells via the bacterial type Ⅲ secretion system(T3SS) during pathogenic interactions. They play a crucial role in disease development by regulating host genes. Despite this, the regulatory mechanisms by which TALEs control OsWRKY transcription factors(TFs) remain poorly understood. In this study, we show that two TALEs from Xanthomonas oryzae pv. oryzae(Xoo) individually modulate two OsWRKY TFs, resulting in increased susceptibility and reduced host defense.Specifically, Xoo1219 and Xoo2145 activate the expression of OsWRKY104 and OsWRKY55, respectively, through direct interactions. OsWRKY104 increases the susceptibility to Xoo by activating OsSWEET11 and OsSWEET14, while OsWRKY55suppresses host defense against Xoo by directly regulating OsWRKY62. These findings suggest that TALEs hijack the host's OsWRKY TFs to create a favorable environment for bacterial survival.
基金supported by the Natural Science Foundation of Liaoning Province(2021-MS-260)。
文摘Transitional metal oxides have a wide range of applications due to their superior properties.The enhanced performance of metal oxide relies on their desirable oxidation states,which is challenging to achieve and requires complex post-processes.This study demonstrates a facile strategy enabling rapid phase transformation of transition metal oxide.The approach involves synthesis of a tetragonal Mn_(3)O_(4)/carbon cloth composite using the liquid plasma discharge deposition(LPDD)technique,followed by laser irradiation with the presence of ethylene glycol under an N_(2)gas environment.The resulting face-centered cubic Mn O/carbon cloth electrode exhibits an excellent capacitance of 1,125 Fg_(-1)at 2 A g^(-1),with remarkable capacitance retention of 95%after 10,000 cycles.This approach can be extended to other transition metals including Co,Cu,Cr,Fe,Ni,and Zn.Computational simulations reveal the significance of ethylene glycol and the underlying mechanism associated with the phase transformation of transition metal oxides.The present study offers a powerful technique for the phase transformation of transition metal oxide which can guide the development of new electrode materials with enhanced electrochemical properties for high-performance energy storage applications.
文摘This study investigates the spatiotemporal trends of key environmental drivers of dust emission over North Africa especially precipitation,surface wind speed,low vegetation leaf area index(LAI),and the Saharan Heat Low(SHL).Using reanalysis data spanning the past four decades(1984-2023),we analyze the spatial trends and assess their statistical significance.The aim is to evaluate how long-term changes in these local meteorological drivers may have contributed to the observed decline in dust activity over North Africa.Results reveal a widespread increase in precipitation and LAI,particularly across the Sahel region(10˚N-20˚N),suggesting enhanced surface wetness and vegetation cover that act to suppress dust mobilization.Simultaneously,a significant negative trend in 10 m wind speed was observed across both the Sahel and parts of Sahara,limiting the surface wind stress required for dust uplift.In contrast,the SHL exhibited a notable intensification and westward expansion,especially over the southern Sahara.Although SHL strengthening is typically associated with increased dust activity,our findings point to a more nuanced role,wherein its recent expansion coincides with broader dust-suppressing environmental trends.These co-evolving changes provide a compelling mechanistic explanation for the observed decline in North African dust activity over recent decades and enhance our understanding and climate models capabilities related to dust activity over North Africa.
基金to King Mongkut’s University of Technology Thonburi(KMUTT)for the Postdoctoral fellowship awarded to him and the Research Network NANOTEC(RNN)program(Grant No:P1851883)of the National Nanotechnology Center(NANOTEC),NSTDA,Ministry of Science and Technology,Thailand that made this work possible.
文摘Carbonaceous materials with large interlayer spacing and disordered structure are considered suitable as electrodes in sodium-ion batteries so as to overcome the problem encountered in conventional electrodes.In this study,carbon quantum dots(CQDs)decorated with SnO_(2)and NaVO_(3)are used as electrodes in the fabrication of flexible Na-ion batteries.CQDs are prepared from dead leaves of the Samanea saman tree through alkaline-peroxide treatment and hydrothermal carbonization.As-prepared CQDs exhibit a quantum yield of 21.03%at an excitation wavelength of 360 nm.Various separators such as indium-doped tin oxide/polyoxyethylene tridecyl ether(ITO/PTE),rice paper(RP),silicone with three big holes(SIL BH),silicone with many small holes(SIL SH)and cellulose paper(CP)have been tried in flexible Na-ion batteries.SIL SH achieved higher specific capacitance(881 F g-1)than other separators due to the function of many small holes on the surface of the silicone.The SIL SH separator delivered higher discharge capacities of 141 and 114 mC g-1 at 1.5 and 2.5 V than SIL BH.The RP separator delivered specific discharge capacities of 1087 and 347 mC g-1 in the 1st and 50th cycles,respectively,at 1 V.The RP separator delivered a high initial specific discharge capacity of 698 mC g-1 at 2 V and maintained a good discharge capacity of 222 mC g-1 in the 50th cycle.As compared to RP,SIL SH delivered high specific discharge capacity of 4246 in 1st cycle at 2 V but maintained a capacity of 71 mC g-1 in the 50th cycle.This study reveals the scope of developing flexible Na-ion batteries with high capacity and cyclability using carbonaceous materials derived from the leaves of the S.saman tree.
文摘Gel-polymer electrolytes with high thermal stability and mechanical properties were considered suitable in rechargeable batteries so as to overcome the problems encountered in liquid electrolytes.In a previous study,flexible sodium-ion batteries(FSIBs)were fabri-cated using electrodes made of carbon quantum dots(CQDs)decorated with SnO_(2) and NaVO_(3) utilizing a polyvinyl alcohol(PVA)/P3HT gel-polymer electrolyte at a ratio of 1:0.05.In addition,various separators such as indium-doped tin oxide/polyoxyethylene tridecyl ether(ITO/PTE),rice paper(RP),silicone with three big holes(SIL BH),silicone with many small holes(SIL SH)and cellulose paper(CP)were tested in flexible Na-ion batteries.The SIL SH delivered a high specific discharge capacity of 4246 mAh g^(-1) in the initial cycle at 2 V and maintained a value of 71 mAh g^(-1) in the 50th cycle.With the aim of improving the cyclic ability of FSIBs,different weight ratios of PVA/P3HT(1:0.025,1:0.05,1:0.1,1:0.15,1:0.2)were tried in this work using the electrodes CQDs@SnO_(2) and CQDs@NaVO_(3).The above ratios were referred to as B25,B50,B100,B150 and B200,respectively.SIL SH was used as a separator.Cyclic voltammetry studies indicated that B150 had a high specific capacitance of 13062 F g^(-1).B25 and B100 exhibited high discharge capacities(171 mAh g^(-1))and(151 mAh g^(-1))compared to that of other ratios B50(75 mAh g^(-1)),B150(88 mAh g^(-1))and B200(54 mAh g^(-1))in the 50th cycle at 2.0 V.This study reveals the scope of developing FSIBs of high capacity and cyclability at different voltages using carbonaceous electrodes and gel-polymer electrolytes with different ratios of PVA/P3HT.The focus of the present study is to bring out the optimum ratio of PVA/P3HT for maximizing the cyclic ability of FSIBs.
基金the National Research Foundation of Singapore(NRF)under its Campus for Re-search Excellence and Technological Enterprise(CREATE)programme(FI 370074011).
文摘Urban infrastructures are invariably constituted by social and technical components whose capacity to withstand crisis is determined by the resilience of their sociotechnical structures.This study aims to apply the principles of sociotechnical resilience in modeling and simulating disaster response in urban areas.Drawing on a case study of Jakarta,Indonesia,our study focuses on the role of hospitals as part of healthcare infrastructure in response to a large-scale disaster.Each hospital is modeled as a coordinated location with a certain amount of resources,primarily in terms of medical staff.We perform sensitivity analysis through Monte Carlo simulations to observe the impacts of various response strategies,disaster severity,and communication duration on system resilience.The results show that centralized systems are generally more suitable for dealing with low disaster severity,while the decentralized strategy performs better during a disaster with worse impacts.Additionally,the time taken for communication and coordination can significantly affect the performance of centralized systems.By simulating various scenarios,parameters,and recovery protocols,the model we developed can help policymakers,city planners,and other stakeholders design proper response strategies suitable to their structural conditions and available resources during a large-scale disaster in urban cities.
基金This work was supported by Singapore MOE Academic Research Fund(AcRF)Tier 1 grant(RG49/18)Additive Manufacturing for Biological Materials(AMBM)program from Singapore A*STAR Science and Engineering Research Council(A18A8b0059).
文摘Silica nanoparticles have been studied extensively in biomedical field due to their high biocompatibility,controllable morphology and so on.They can be used both as the drug carrier and imaging vehicle.Here,an aminated ultra-small silica nanoparticle based system is developed with various functionalities.Multiple molecules including fluorophore,folic acid,and antibody are coupled to this system to achieve specific applications such as bacterial/cell labelling and recognition.
